This invention generally relates to systems and methods for minimizing the voids and/or porosity of bonded joints (e.g., bonded aircraft joints) fabricated using adhesives. As used herein, the term “adhesive” comprises resins, film adhesives and paste adhesives.
Known methods of fabricating bonded joints using paste adhesives leave voids and/or porosity in the bondline once the laminates are bonded together. These voids reduce the mechanical properties that, optimally, should be exhibited by the adhesive. This reduction in properties is especially true for paste adhesives with higher viscosities that tend to retain entrapped air more than less viscous adhesives.
It is known that the application of positive pressure in an autoclave can be used to reduce the size of voids by reducing their volume. In many cases autoclaves are not feasible for use, so vacuum bag processes are used. The resulting bonded repairs were either used as-is with porosity and/or voids, or they were reprocessed until acceptable joints were fabricated.
There is a need for a solution for eliminating or minimizing voids and porosity in the bondlines of paste adhesive, film adhesive or resin system coupons without the use of high-pressure autoclaves.